This example shows how a VTM control system can be implemented using a state machine. There is no cooling system or A/C system modeled explicitly, but instead both the evaporator and the PTC heater in the HVAC box are represented by area resistances with heat sources. The HVAC blower is modeled as an air mass flow source. The focus is put on the control subsystem, which automatically engages cooling or heating modes according to cabin temperature levels and controls heater, evaporator, fan and HVAC flaps so that a target temperature is reached in a specific cabin zone. This subsystem is made mostly generic and with simple interfaces to allow easy re-use in a wide range of applications. Additionally the cabin model shows an application of the “variable flow fields” feature to correctly reproduce different conditions during heating (air goes to legroom) and cooling (air goes to passenger vents).
Keywords: VTM, VCU, control, state machine, HVAC, comfort, cabinUsable from release: KULI 13